It turns out the startup code in csu/elf-init.c has a perfect pair of
ROP gadgets (see Marco-Gisbert and Ripoll-Ripoll, "return-to-csu: A
New Method to Bypass 64-bit Linux ASLR"). These functions are not
needed in dynamically-linked binaries because DT_INIT/DT_INIT_ARRAY
are already processed by the dynamic linker. However, the dynamic
linker skipped the main program for some reason. For maximum
backwards compatibility, this is not changed, and instead, the main
map is consulted from __libc_start_main if the init function argument
is a NULL pointer.
For statically linked binaries, the old approach based on linker
symbols is still used because there is nothing else available.
A new symbol version __libc_start_main@@GLIBC_2.34 is introduced because
new binaries running on an old libc would not run their ELF
constructors, leading to difficult-to-debug issues.
Linux 5.11 has one new syscall, epoll_pwait2. Update
syscall-names.list and regenerate the arch-syscall.h headers with
build-many-glibcs.py update-syscalls.
Tested with build-many-glibcs.py.
Currently glibc has three different struct statfs{64} definitions:
1. Non-LFS support where non-LFS and LFS struct have different
size: alpha, arm, hppa, i686, m68k, microblaze, mips (all abis),
powerpc32, s390, sh4, and sparc.
2. Non-LFS support where non-LFS and LFS struct have the same
size: csky and nios2.
3. Only LFS support (where both struct have the same size): arc,
ia64, powerpc64 (including LE), riscv (both 32 and 64 bits),
s390x, sparc64, and x86 (including x32).
The STATFS_IS_STATFS64/__STATFS_MATCHES_STATFS64 does not tell apart
between 1. and 2. since for both the only difference is the struct
size (for 2. both non-LFS and LFS uses the same syscall, where for
1. the old non-LFS is used for [f]statfs).
This patch move the generic statfs.h for both csky and nios2, and
make the default definitions for newer ABIs to assume that only
LFS will be support (so there is no need to keep no-LFS and LFS
struct statfs with the same size, it will be implicit).
This patch does not change the code generation.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The XSTAT_IS_XSTAT64 and STAT_IS_KERNEL_STAT flags are now set to 1 and
STATFS_IS_STATFS64 is set to __STATFS_MATCHES_STATFS64. This makes the
default ABI for newer ports to provide only LFS calls.
A copy of non-LFS support is provided to 32-bit ABIS with non-LFS
support (arm, csky, i386, m68k, nios2, s390, and sh). Is also allows
to remove the 64-bit ports, which already uses the default values.
This patch does not change the code generation.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
Linux 5.10 has one new syscall, process_madvise. Update
syscall-names.list and regenerate the arch-syscall.h headers with
build-many-glibcs.py update-syscalls.
Tested with build-many-glibcs.py.
It removes all the arch-specific assembly implementation. The
outliers are alpha, where its kernel ABI explict return -ENOMEM
in case of failure; and i686, where it can't use
"call *%gs:SYSINFO_OFFSET" during statup in static PIE.
Also some ABIs exports an additional ___brk_addr symbol and to
handle it an internal HAVE_INTERNAL_BRK_ADDR_SYMBOL is added.
Checked on x86_64-linux-gnu, i686-linux-gnu, adn with builsd for
the affected ABIs.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Linux 5.9 has one new syscall, close_range. Update syscall-names.list
and regenerate the arch-syscall.h headers with build-many-glibcs.py
update-syscalls.
Tested with build-many-glibcs.py.
This patch removes the mknod and mknodat static wrapper and add the
symbols on the libc with the expected names.
Both the prototypes of the internal symbol linked by the static
wrappers and the inline redirectors are also removed from the installed
sys/stat.h header file. The wrapper implementation license LGPL
exception is also removed since it is no longer statically linked to
binaries.
Internally the _STAT_VER* definitions are moved to the arch-specific
xstatver.h file.
Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
This patch removes the stat, stat64, lstat, lstat64, fstat, fstat64,
fstatat, and fstatat64 static wrapper and add the symbol on the libc
with the expected names.
Both the prototypes of the internal symbol linked by the static
wrappers and the inline redirectors are also removed from the installed
sys/stat.h header file. The wrapper implementation license LGPL
exception is also removed since it is no longer statically linked to
binaries.
Internally the _STAT_VER* definitions are moved to a arch-specific
xstatver.h file. The internal defines that redirects internals
{f}stat{at} to their {f}xstat{at} counterparts are removed for Linux
(!NO_RTLD_HIDDEN). Hurd still requires them since {f}stat{at} pulls
extra objects that makes the loader build fail otherwise (I haven't
dig into why exactly).
Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
This patch adds the ABI-related bits to reflect the new mallinfo2
function, and adds a test case to verify basic functionality.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Linux 5.8 has one new syscall, faccessat2. Update syscall-names.list
and regenerate the arch-syscall.h headers with build-many-glibcs.py
update-syscalls.
Tested with build-many-glibcs.py.
The kernel ABI is not finalized, and there are now various proposals
to change the size of struct rseq, which would make the glibc ABI
dependent on the version of the kernels used for building glibc.
This is of course not acceptable.
This reverts commit 48699da1c4 ("elf:
Support at least 32-byte alignment in static dlopen"), commit
8f4632deb3 ("Linux: rseq registration
tests"), commit 6e29cb3f61 ("Linux: Use
rseq in sched_getcpu if available"), and commit
0c76fc3c2b ("Linux: Perform rseq
registration at C startup and thread creation"), resolving the conflicts
introduced by the ARC port and the TLS static surplus changes.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The strerrorname_np returns error number name (e.g. "EINVAL" for EINVAL)
while strerrordesc_np returns string describing error number (e.g
"Invalid argument" for EINVAL). Different than strerror,
strerrordesc_np does not attempt to translate the return description,
both functions return NULL for an invalid error number.
They should be used instead of sys_errlist and sys_nerr, both are
thread and async-signal safe. These functions are GNU extensions.
Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
and s390x-linux-gnu.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The sigabbrev_np returns the abbreviated signal name (e.g. "HUP" for
SIGHUP) while sigdescr_np returns the string describing the error
number (e.g "Hangup" for SIGHUP). Different than strsignal,
sigdescr_np does not attempt to translate the return description and
both functions return NULL for an invalid signal number.
They should be used instead of sys_siglist or sys_sigabbrev and they
are both thread and async-signal safe. They are added as GNU
extensions on string.h header (same as strsignal).
Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
and s390x-linux-gnu.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The variable is placed in libc.so, and it can be true only in
an outer libc, not libcs loaded via dlmopen or static dlopen.
Since thread creation from inner namespaces does not work,
pthread_create can update __libc_single_threaded directly.
Using __libc_early_init and its initial flag, implementation of this
variable is very straightforward. A future version may reset the flag
during fork (but not in an inner namespace), or after joining all
threads except one.
Reviewed-by: DJ Delorie <dj@redhat.com>
Register rseq TLS for each thread (including main), and unregister for
each thread (excluding main). "rseq" stands for Restartable Sequences.
See the rseq(2) man page proposed here:
https://lkml.org/lkml/2018/9/19/647
Those are based on glibc master branch commit 3ee1e0ec5c.
The rseq system call was merged into Linux 4.18.
The TLS_STATIC_SURPLUS define is increased to leave additional room for
dlopen'd initial-exec TLS, which keeps elf/tst-auditmany working.
The increase (76 bytes) is larger than 32 bytes because it has not been
increased in quite a while. The cost in terms of additional TLS storage
is quite significant, but it will also obscure some initial-exec-related
dlopen failures.
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
Use __getline instead of __getdelim to avoid a localplt failure.
Likewise for __getrlimit/getrlimit.
The abilist updates were performed by:
git ls-files 'sysdeps/unix/sysv/linux/**/libc.abilist' \
| while read x ; do
echo "GLIBC_2.32 pthread_getattr_np F" >> $x
done
python3 scripts/move-symbol-to-libc.py --only-linux pthread_getattr_np
The private export of __pthread_getaffinity_np is no longer needed, but
the hidden alias still necessary so that the symbol can be exported with
versioned_symbol.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
The abilist updates were performed by:
git ls-files 'sysdeps/unix/sysv/linux/**/libc.abilist' \
| while read x ; do
echo "GLIBC_2.32 pthread_getaffinity_np F" >> $x
done
python3 scripts/move-symbol-to-libc.py pthread_getaffinity_np
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
The symbol did not previously exist in libc, so a new GLIBC_2.32
symbol is needed, to get correct dependency for binaries which
use the symbol but no longer link against libpthread.
The abilist updates were performed by:
git ls-files 'sysdeps/unix/sysv/linux/**/libc.abilist' \
| while read x ; do
echo "GLIBC_2.32 pthread_attr_setaffinity_np F" >> $x
done
python3 scripts/move-symbol-to-libc.py pthread_attr_setaffinity_np
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
A new symbol version is added on libc to force loading failure
instead of lazy binding one for newly binaries with old loaders.
Checked with a build against all affected ABIs.
Linux 5.6 has new openat2 and pidfd_getfd syscalls. This patch adds
them to syscall-names.list and regenerates the arch-syscall.h files.
Tested with build-many-glibcs.py.
It is necessary to export __pthread_cond_init from libc because
the C11 condition variable needs it and is still left in libpthread.
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It is necessary to export __pthread_cond_destroy from libc because
the C11 condition variable needs it and is still left in libpthread.
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Exporting functions and relying on symbol interposition from libc.so
makes the choice of implementation dependent on DT_NEEDED order, which
is not what some compiler drivers expect.
This commit replaces one magic mechanism (symbol interposition) with
another one (preprocessor-/compiler-based redirection). This makes
the hand-over from the minimal malloc to the full malloc more
explicit.
Removing the ABI symbols is backwards-compatible because libc.so is
always in scope, and the dynamic loader will find the malloc-related
symbols there since commit f0b2132b35
("ld.so: Support moving versioned symbols between sonames
[BZ #24741]").
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
With all Linux ABIs using the expected Linux kABI to indicate
syscalls errors, the INTERNAL_SYSCALL_DECL is an empty declaration
on all ports.
This patch removes the 'err' argument on INTERNAL_SYSCALL* macro
and remove the INTERNAL_SYSCALL_DECL usage.
Checked with a build against all affected ABIs.
With all Linux ABIs using the expected Linux kABI to indicate
syscalls errors, there is no need to replicate the INLINE_SYSCALL.
The generic Linux sysdep.h includes errno.h even for !__ASSEMBLER__,
which is ok now and it allows cleanup some archaic code that assume
otherwise.
Checked with a build against all affected ABIs.
The new tables are currently only used for consistency checks
with the installed kernel headers and the architecture-independent
system call names table. They are based on Linux 5.4.
The goal is to use these architecture-specific tables to ensure
that system call wrappers are available irrespective of the version
of the installed kernel headers.
The tables are formatted in the form of C header files so that they
can be used directly in an #include directive, without external
preprocessing. (External preprocessing of a plain table file
would introduce cross-subdirectory dependency issues.) However,
the intent is that they can still be treated as tables and can be
processed by simple tools.
The irregular system call names on 32-bit arm add a complication.
The <fixup-asm-unistd.h> header is introduced to work around that,
and the system calls are listed under regular names in the
<arch-syscall.h> file.
A make target, update-syscalls-list, is added to patch the glibc
sources with data from the current kernel headers.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
